ic7b03168_si_001.pdf (2.65 MB)
Temperature Effect on Co-Based Catalysts in Oxygen Evolution Reaction
journal contribution
posted on 2018-02-22, 16:51 authored by Guangxing Zhang, Han Wang, Jinlong Yang, Qinghe Zhao, Luyi Yang, Hanting Tang, Chaokun Liu, Haibiao Chen, Yuan Lin, Feng PanOxygen evolution
reaction (OER), as the critical step in splitting water, is a thermodynamically
“up-hill” process and requires highly efficient catalysts
to run. Arrhenius’ law suggests that the higher temperature,
the faster the reaction rate, so that a larger OER current density
can be achieved at a lower η. Herein, we report an abnormal
temperature effect on the performance of Co-based catalysts, e.g.,
Co3O4, Li2CoSiO4, and
Fe-doped Co(OH)x, in OER in alkaline electrolytes.
The OER performance reached a maximum when the temperature increased
to 65 °C, and the OER performance declined when the temperature
became higher. The mechanism was investigated by using Co3O4 as a model sample, and we propose that at an optimal
temperature (around 55–65 °C) the main rate-determining
step changes from OH– adsorption dominant to a mixed
mode and both the adsorption and the cleavage of the OH group can
be rate-determining, which leads to the fastest kinetics.